Telemetry (Small Animals)
Traditional tethered systems limit the recording environment when monitoring physiological signals such as blood pressure, ECG, EMG, EEG, EOG and nerve activity in conscious animals. Telemetry is based on wireless technology that allows recording and transfer of information from a remote system. Typically a small wireless transmitting device (transmitter or “telemeter”) is implanted in an animal, or attached to a subject, and it transmits via radio-frequency communication to a receiver unit located elsewhere. This allows the animal or subject to move around freely without being limited by any tethered wires.
LabChart software and PowerLab hardware can be used with third-party Telemetry systems to record and analyze long-term wireless monitoring/recordings in freely moving small laboratory animals. Depending on the telemeters (previously known as transmitters) a variety of signals can be recorded including pressure (intravascular or intralumen pressure), biopotentials (ECG, EMG, EOG or EEG signals) and sympathetic nerve activity (SNA). ADInstruments does not supply Telemeters.
The implantation of the telemeters requires specialized surgical techniques. The following processes are recommended to ensure rapid recovery and minimize adverse health effects:
- Maintain a constant animal body temperature during surgery. This may be achieved using the ADInstruments Homeothermic Controller and Plate.
- Minimize the dead space surrounding the implanted telemeter. It is recommended that the Telemeter body be placed inside the abdominal cavity, while the electrodes/catheter can be tunnelled subcutaneously to the recording site.
- Use blunt dissection techniques to minimize tissue damage.
- Ensure sterile surgical techniques are used to avoid infection.
- Allow adequate time for the animal to recover (up to 1 week) before recording physiological signals.
The LabChart Advantage:
- LabChart features Sampling from Multiple Devices (Windows only), which allows the user to record a maximum of 32 channels of live data using multiple PowerLab units into a single LabChart file. Therefore, with the use of two 16 channel PowerLabs, i.e. 32 channels of recording, the user can record from:
- Up to 16 single small animal telemeters (Maximum 2 signals from each telemeter)
- Up to 10 dual small animal telemeters (Maximum 3 signals from each telemeter)
- The ECG Analysis Module can average ECG cycles and calculate, display and record PQRST intervals and amplitudes.
- The HRV Module provides analysis, display and reporting of variability in ECG and pulse recordings.
- The Blood Pressure Module calculates and displays numerous cardiovascular parameters from arterial and ventricular pressure recordings including; mean pressure, pressure maxima and minima, dP/dt, end-diastolic pressure, contractility and more.
- The Circadian Analysis Module is ideal for analysis of long-term recordings and provides offline analysis of trends in data.
- The Spike Histogram Module can detect, discriminate and analyze extracellular neural spike activity.
- The Peak Analysis Module provides automatic detection and analysis of multiple, but not overlapping, signal peaks in acquired waveforms.
- Schedule recordings with the LabChart Scheduler Extension.
LabChart software (for Windows and Macintosh) together with a PowerLab data acquisition system offers up to 32 channels of real-time data acquisition, data integrity, easy selection of hardware settings, powerful online and offline analysis, procedure automation, seamless extraction of experimental data and flexible display options. Additional acquisition and analysis functionality is provided with the use of specialized LabChart Extensions and LabChart Modules. Modules are available as part of LabChart Pro while Extensions are free for download from the website for existing LabChart users.
ECG Analysis Module
The ECG Analysis Module (Windows) provides a comprehensive set of tools that automatically detects and reports values of ECG recordings.
- Real-time analysis and data extraction of ECG parameters
- PQRST amplitudes
- Time intervals such as RR, PR, JT, QT and QTc
- Analysis of ECG parameters in real-time or offline
- Automated detection and averaging of ECG cycles
- Automated tabulation and data extraction of ECG parameters
- Automated real-time or offline ECG Plots
- Graphical QT vs RR, QT vs Time & RR vs Time plots
- Waterfall plot
Heart Rate Variability (HRV) Module
The HRV Module:
- Detects and analyzes R waves & RR interval variation in ECG real-time or offline recordings
- Includes or excludes ectopic beats from analysis
- Adds R waves or remove short artifacts from analysis
- Provides data export options such as Text, Excel, EDF, WAV, etc
- Provides automated HRV Analysis Windows including:
- Poincare Plot
- Period Histogram
- Delta R Histogram
- Power Spectrum
- Summary Report
Blood Pressure Module
The Blood Pressure Module (Windows) automatically detects, analyzes and reports cardiovascular parameters from arterial or ventricular pressure signals.
- Real-time analysis and data extraction of pressure parameters
- Max and min pressures
- Max and min dP/dt
- Analysis of blood and cardiac pressure in real-time or offline
- Automated detection of pressure cycles
- Automated tabulation and data extraction of pressure parameters
- Analysis View
- Averaging of pressure waveforms
- Automated pressure parameter labelling
Circadian Analysis Module
The Circadian Analysis Module (Windows) analyzes data with a daily pattern and generates graphical and tabular views of the daily and averaged circadian data. The Circadian Analysis Module features:
- Circadian Analysis Settings dialog which allows;
- Selection of channels to be included for analysis
- Customizable time settings including day length, start time and averaging interval
- A data exclusion filter which ignores data that falls outside preset upper and lower limits
- Light on/off shading to demonstrate night and day in the Averaging View
- Analysis Averaging View plots average interval data for single or multiple channels. You can choose to view the Average day, or show all days overlayed on top of the Average day.
- Circadian Analysis Table View automatically displays calculated parameters for each single day. These parameters include:
- Time at Maximum
- Time at Minimum
- Exportable Analysis Averaging View plot and Table View as text or image formats
Spike Histogram Module
The Spike Histogram Module (Windows or Macintosh) provides the ability to detect, discriminate and analyze extracellular neural spike activity online. Recorded spikes can also be reanalyzed offline with modified discrimination settings.
The Spike Histogram Module:
- Provides easy to use spike discrimination and data analysis
- Automatically indicates and examines changes in neural firing rate
- Automatically determines the distribution of all interspike intervals
- Performs auto- and cross-correlation analysis (Mac only)
- Saves data in .nex format for easy transfer to NeuroExplorer software for further analyses (Windows only)
Peak Analysis Module
The Peak Analysis Module (Windows) provides automatic detection and analysis of multiple, but not overlapping, signal peaks in acquired waveforms. It can be applied to a wide range of waveforms including recorded signals from:
- Isolated tissue studies
- Hemodynamic measurements
- Cardiac physiology
- Current measurements.
- Real-time or offline analysis
- Fast parameter extraction and analysis from single or multiple peaks
- Automatic peak detection of an entire channel or a selection within a channel
- Detection of positive or negative peaks
- Several analysis presets suitable for general and specific types of waveforms
- Evoked Response, Population Spike, Synaptic, Action Potential and Cardiac Action Potential
- Instant tabulation of extracted parameters that can be exported to other applications
- Height, width, area of the peak and time to peak
The Scheduler Extension (Windows) allows the scheduling of recordings across one or more LabChart data files. A schedule may consist of an initial delay, followed by repeated recording cycles, until a specified end time.
GLP and 21 CFR Part 11
For those researchers working within a laboratory requiring GLP and 21 CFR Part 11 compliance the GLP Client and GLP Server are available for use with LabChart (Windows only) and PowerLab data acquisition systems. For more information, visit the Good Laboratory Practice application page or contact your nearest ADInstruments representative.
PowerLab Data Acquisition Systems
The PowerLab is a high-performance data acquisition unit capable of recording at speeds of up to 400,000 samples per second continuously to disk (aggregate). PowerLab units are compatible with instruments, signal conditioners and transducers supplied by ADInstruments, as well as many other third-party companies. In addition to standard single-ended BNC inputs, 4 differential Pod ports are also available for direct connection of Pod signal conditioners and appropriate transducers. Research PowerLab units include:
- (2007) Novel technology for the provision of power to implantable physiological devices Journal of Applied Physiology, 102: 1658-1663
- (2008) Persistent alterations in heart rate variability, baroreflex sensitivity, and anxiety-like behaviors during development of heart failure in the rat American Journal of Physiology: Heart and Circulatory Physiology, 295: H29H38
- (2009) Detection of low-frequency oscillations in renal blood flow American Journal of Physiology: Renal Physiology, 297: F155-F162